I know people that had difficulties with this exam as well, its not the end of the world though

What I suggest for you to do, is get back to your instructor and ask him/her for advice and for more information, material and mock exams, they will be the best people to guide you on this. If you are doing it online, then I suggest you to search for the online CBTs there are some good ones out there. But as I said your trainer is the person you should be refering to not anyone else..